Process for the production of washable printings on leather



Patented June 4, 19 2 9.

UNITED STATES- cnAnLns s.

rnmmmn, or PARIS, rRAncE, nssrenon '10 sacrum: nncmns ETAIB- nIssnmENrs ,A. corner: a FILS & cm, or. PARIS, FRANCE.

PROCESS FOR PRODUCTION OF WASHAIBLE PRINTINGS ON LEATHER.

No I Drawing. Application filed April 13, 1923, Serial No. 631,954, and in France November 30, 1922.

Heretofore, the only hides or'skins used for the production of printings were those which have been tanned with vegetal substances, like those which are used for making moroc- 5 co-leather goods, for furniture, book-bindings, fancy articles, millinery and dressmaking. Besides this, the leather and the printing would ,not resist washing.

The presentinvention relates to a process for producing washable printings upon leather, with the purpose of obtaining articles, which'besides'being adapted for the above mentioned purposes, may compete with the polychromati'c fabrics as used actually I for shoes, slippers and the like, which they tanning operation in a bath of powdered sumach or any other similar substance, for an hour, at a'temperature of 35 C.

They are for instance mechanically treated in the usual manner in order to give them the appearance of velvet, or suede leather; in other words, the hides or skins receive an ooze or suede, or any other, finish.

After having been dried at C., the hides 35 or skins are then ready to be printed.- This operation is performed by means of engraved plates, with the employment, for example, of the following mixture: 4

6 a 25 to 30grams of dye-stuff (Rhodamine).

' 200 to 500 grams of tragacanth. v 40 to 60 grams of acetate of chrome.

5 to 10 grams of tannic acid. 5- to '10 grams of glycerine. 2 liters of water.

The'printing colours can be applied upon any ground color or the ground color can be obtained after printing.

After the printing operation has taken place, the hides or skins are placed in a steam room, for about one hour, at a temperature of 75 C.

'iihis steaming has for its purpose, the thor- 'timately associates itself with the fibres of derstood by those skilled in the art, the morough penetration of the dye-stufi -which, prior to this operation, was but superficial. Moreover this treatment in the steam room means a step towards the fixing which is effected by employing the usual pigments or mordants and is accomplished in a bath of emetic, such as tartar emetic, or of acid, according to the nature of the dye-stufis used.

The acid or metallic mordants are employed to temporarily fix the dyestuffs which have been applied; but their main purpose is to form a chemical combination which inthe leather, after a stay in the emetic and acid baths. Any color may be used in carrying out the process and as may be readily un- I dant employed will depend. upon the color use I The hides or skins are then washed in clear water; they are thus ready to be used for the manufacture of the articles for which they they are intended. a

The leather thus printed retains, after washing all its properties as to softness and strength; moreover the penetration of the dye-stuff is deep enough,- so that the colors will not fade after a certain timeof use.

It must be observed that the above figures and details for carrying out the invention have been given only by way of example and that they can be modified without departing from the principle of the invention.

For instance, the tanning with formol could easily be replaced by a tawing process with the use of formol or alum.

What I claim is:

1. A process for the manufacture of washable printed leather which consists in preparing the hide or skin for the subsequent printing, steaming and fixing steps, by tanning the hide or skin first with formol, and i then tanning the same in a bath of powdered sumac.

2. In a production of washable color'printed leather, the process which consists in subjecting the skin to successive tannings, first 100. with formol and then with sumac, and subsequently printing the same.

In testimony whereof I have signed this specification.

CHARLES s. FRIEDMAN. 

